She has been labelled a cold fish, a troublemaker and a bit of a lightweight - glancing through what has been written about Baroness Susan Greenfield, it quickly becomes evident that she has attracted more than her fair share of criticism.

Why this should be so is a bit of a mystery to her and those who know her well, but what there is no doubt about is her string of glittering achievements as one of Britain's brightest and best-known scientists.

She combines her role as professor of pharmacology at the University of Oxford with a myriad of other high-flying positions, such as being the first woman director of that most hallowed of all scientific bodies, The Royal Institution, a people's peer in the House of Lords and the holder of 29 honorary degrees.

Not bad for someone who didn't like science at school, doesn't have a single science O-Level and studied Latin, Greek, history and mathematics for A-Level.

"I couldn't see the point of science at school. In chemistry, we had to distil water but no one told me what distilled water was, why it is interesting, or why you would want to do it," she explained.

"Similarly in biology, there was no opportunity for any creative input, you just had to copy down what the teacher dictated and it was all rather dreary.

"It all seemed so far removed from my everyday life, no one ever put any of it into context so I couldn't see why I was learning those things," she added.

This refreshing honesty and down-to-earth approach may be one of the root causes of why she has ruffled the feathers of some of her peers within the scientific community.

Her own experience as a latecomer to science - she arrived at St Hilda's to study classics, switched to philosophy then did psychology before finally coming to neuro science - has left her keen to demystify the subject.

"People don't say I haven't got a degree in English literature, therefore I can't read Dickens,' do they?" she asked. "I don't see why science should be any different. Some of the concepts are more esoteric but they are relatively simple to understand in basics.

"It is really important to empower people and to help them rather than sneer at them and tell them they don't understand.

"It is the fault of us scientists if we can't see the wood for the trees and explain that to the general public," she added.

Her ability to look at things from an outsider's viewpoint and communicate clearly to a non-scientific audience is one of her most outstanding qualities but once again, has not always gone down well.

"In science you are defined by what you know and the whole coinage is in knowing more than other people. A scientist can be trumped easily if someone says You are wrong, this fact has just emerged that you didn't know'.

"Because of that, you focus on a very narrow range because you can't police the facts on a wide range of subjects.

"You become the expert in that area and that defines you. So how would you feel if someone came along and was able to explain your area of expertise very quickly and easily to the general public? You wouldn't like it, would you?" she pointed out. Her speciality is the physiology of the brain and she has worked tirelessly to research and bring attention to unfashionable diseases such as Parkinson's and Alzheimer's.

There was no personal reason for choosing this area of specialism, as might be imagined.

"My father is 92, my mother 80 and they are both fizzing with health. I am so proud of them," she said.

"I was working on the basic mechanisms of the brain and it just happened that what I discovered was of relevance to neuro degeneration. I didn't set out to solve the riddle of Alzheimer's or Parkinson's, rather that what I did turned out to be applicable to those conditions," she explained.

She has never been one for planning when it comes to her career, preferring to respond to opportunities as they arise.

"Some things have come utterly out of the blue, such as being asked to give the televised Royal Society Christmas lectures in 1994. That was exciting and the beginning of me doing things in the public eye.

"Science is like that and that is why I love it. You never know what is going to happen in an experiment and the whole point is that you mustn't be blinkered by preconceived ideas. If something new does occur you have to be ready to run with it. And that is how it is in life," she added.

Another unexpected career opening was an invitation to go to Australia as Adelaide's thinker in residence in 2004 and 2005.

"I made wonderful friends there and learned a lot. I now adore visiting Australia and go once or twice a year," she said.

Although she has strong opinions, she comes across as someone who is open minded and enjoys being presented with a differing point of view.

She looks far younger than her 57 years and has an energy about her that makes it easy to imagine her inspiring work colleagues on her ground-breaking research.

"People either seem to like working with me a lot, or fall out quite quickly. I take it as a given that people are enthusiastic so if they aren't, it leaves me cold," she admitted.

"If people are lukewarm, I find it demoralising while being with people who are really switched on is inspirational.

"They don't have to know a lot and they can make mistakes. What matters is they are passionate about what they are doing".

She is keen to give others a chance, as she feels her own career owes itself to people who did exactly that with her - most notably her Oxford tutor, Jane Mellanby, still a friend and mentor, who suggested You should be a scientist. It'll be a hoot!' "She sent me to see a professor who asked me did I know what a millimolar solution was. In science, that's like asking someone if they have heard of Shakespeare.

"Of course, I didn't know but he was wonderful. He said Never mind, you can tell us about Homer in the coffee breaks," she recalled.

"I think he took a punt on me because I was enthusiastic. A lesson I have learned is not to dismiss someone just because they don't tick all the boxes," she added.

Once in, she had to work twice as hard as those with a science background.

"I'd never been in a lab before, so weighing out and making up solutions was alien to me. I hadn't even done it in a kitchen because I hated cooking," she laughed.

That hasn't changed, she still doesn't cook at her Oxford flat, preferring to meet up with friends and eat out in the city's bars and restaurants regularly.

Her life is busy though not manic and she clearly thrives on the variety that comes from juggling her research work with TV and radio presenting, sitting in the House of Lords and judging on various scientific panels.

She is also the author of a number of books and has fronted her own TV series, The Private Life of the Brain.

"I am the proverbial jack-of- all trades, in that I like having a wide range of different activities. The saddest thing is to just do one thing," she said.

She has been portrayed as a workaholic, much being made of the fact that she starts her day at 5am.

"I do wake early but wouldn't say I was fully functional at that time, I listen to the BBC's World Service. And, I am useless with late nights," she said.

Her work/life balance seems healthy, despite what her critics say. She plays squash twice weekly, travels extensively for pleasure, as well as business and is close to her family.

"I like to draw a line under work and relax in the evenings. It is great to be with friends who are not scientists as it makes you see things from a different perspective."

She has also come under fire for her comments on work: "I don't advocate that people should work all the time and disregard their home life, I like to see people for whom work is part of their lives.

"Not their whole life but part of it, rather than it being some undesirable activity that they have to minimise and put up with," she explained.

One of her biggest bugbears is the way her appearance is constantly commented on. The fact that she wears fashionable clothes and make-up doesn't seem to fit with some observers' ideas of what a female scientist should look like.

Then there's the charge that she is too much of a self-publicist and the intrusion into her private life - there was much prurient interest when she and distinguished chemistry researcher Peter Atkins divorced in 2004 after 13 years of marriage.

All this she admits is hurtful, though she seems resigned to it. "I don't like it but I'm not going to whinge about it. You've got to take it on the chin.

"People living in Baghdad might not think it is really up there compared to the trials and tribulations they have to put up with.

"Stuff happens, so the issue is how you turn it into a positive."

She shrugged. "The more individual you are trying to be, the stronger the likelihood you won't have an easy ride."